With a personal computer or a portable music player, music data of several thousand music pieces can be stored in its recording medium such as an HDD and selectively played for pleasure. Further, an environment is being established where unknown music data is easily obtained via the Internet.
Users have a desire to quickly select various music pieces according to the situation by utilizing the merit that as many as several thousand music pieces including known and unknown ones can be stored. To date, there have been proposed an apparatus for searching for music pieces according to a specified condition such as the preference of a user or a specific musical mood and an apparatus which using a listening history of a user and listening histories of others, outputs a music piece that matches the preference of the user and is unfamiliar to him/her.
For example, in Japanese Patent Application Laid-Open Publication No. 2005-018205 (Reference 1), there is shown a music piece search apparatus which associates the taste degree of a user (the numbers of play times in the past for music pieces, or an input from the user) with characteristic amounts of music pieces according to a predetermined algorithm beforehand and outputs information about a plurality of music pieces similar to each other that match the taste degree of the user at the request of the user.
In Japanese Patent Application Laid-Open Publication No. 2006-277880 (Reference 2), there is shown collaborative filtering which checks a music piece play list owned by a user against a music piece play list owned by another than the user and, if there are music pieces common to both lists, presents information about the other music pieces contained in the other's music piece play list to the user.
Further, in Japanese Patent Application Laid-Open Publication No. 2005-301160 (Reference 3), there is shown an apparatus which determines the impressions of music pieces according to their characteristics beforehand and, when the user specifies a specific impression, outputs information about music pieces matching it.
With these conventional apparatuses, a user can confirm whether the output result is good or bad, that is, whether the result matches the request of the user depending on the music pieces outputted. However, if the output music pieces are unknown, the user needs to listen to them at least once in order to realize their contents.